package com.atguigu.gulimall.seckill.service.impl;

//import com.alibaba.csp.sentinel.Entry;
//import com.alibaba.csp.sentinel.SphU;
//import com.alibaba.csp.sentinel.annotation.SentinelResource;
//import com.alibaba.csp.sentinel.slots.block.BlockException;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.TypeReference;
import com.atguigu.common.to.mq.SeckillOrderTo;
import com.atguigu.common.utils.R;
import com.atguigu.common.vo.MemberRespVo;
import com.atguigu.gulimall.seckill.feign.CouponFeignService;
import com.atguigu.gulimall.seckill.feign.ProductFeignService;
import com.atguigu.gulimall.seckill.interceptor.LoginUserInterceptor;
import com.atguigu.gulimall.seckill.service.SeckillService;
import com.atguigu.gulimall.seckill.to.SeckillSkuRedisTo;
import com.atguigu.gulimall.seckill.vo.SeckillSessionWithSkusVo;
import com.atguigu.gulimall.seckill.vo.SkuInfoVo;
import com.baomidou.mybatisplus.core.toolkit.IdWorker;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.BooleanUtils;
import org.redisson.api.RSemaphore;
import org.redisson.api.RedissonClient;
import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.BoundHashOperations;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;
import org.springframework.util.CollectionUtils;
import org.springframework.util.StringUtils;

import java.util.*;
import java.util.concurrent.TimeUnit;
import java.util.regex.Pattern;
import java.util.stream.Collectors;

@Slf4j
@Service
public class SeckillServiceImpl implements SeckillService {

    @Autowired
    private StringRedisTemplate redisTemplate;

    @Autowired
    private CouponFeignService couponFeignService;

    @Autowired
    private ProductFeignService productFeignService;

    @Autowired
    private RedissonClient redissonClient;

    @Autowired
    private RabbitTemplate rabbitTemplate;

    private final String SESSION__CACHE_PREFIX = "seckill:sessions:";

    private final String SECKILL_CHARE_PREFIX = "seckill:skus";

    private final String SKU_STOCK_SEMAPHORE = "seckill:stock:";

    @Override
    public void uploadSeckillSkuLatest3Days() {
        //1、扫描最近三天的商品需要参加秒杀的活动
        R lates3DaySession = couponFeignService.getLates3DaySession();
        if (lates3DaySession.getCode() == 0) {
            //上架商品
            List<SeckillSessionWithSkusVo> sessionData = (List<SeckillSessionWithSkusVo>) lates3DaySession.getData(new TypeReference<List<SeckillSessionWithSkusVo>>() {},"data");
            if (CollectionUtils.isEmpty(sessionData)) {
                return;
            }
            //缓存到Redis
            //1、缓存活动信息
            saveSessionInfos(sessionData);
            //2、缓存活动的关联商品信息
            saveSessionSkuInfo(sessionData);
        }

    }

    /**
     * 缓存秒杀活动信息
     */
    private void saveSessionInfos(List<SeckillSessionWithSkusVo> sessions) {
        sessions.forEach(session -> {
            //获取当前活动的开始和结束时间的时间戳
            long startTime = session.getStartTime().getTime();
            long endTime = session.getEndTime().getTime();
            //存入到Redis中的key
            String key = SESSION__CACHE_PREFIX + startTime + "_" + endTime;
            //判断Redis中是否有该信息，如果没有才进行添加
            if (BooleanUtils.isNotTrue(redisTemplate.hasKey(key))) {
                //获取到活动中所有商品的skuId
                List<String> skuIds = session.getRelationSkus().stream()
                        .map(item -> item.getPromotionSessionId() + "-" + item.getSkuId().toString()).collect(Collectors.toList());
                redisTemplate.opsForList().leftPushAll(key,skuIds);
            }
        });
    }

    /**
     * 缓存秒杀活动所关联的商品信息
     */
    private void saveSessionSkuInfo(List<SeckillSessionWithSkusVo> sessions) {
        sessions.forEach(session -> {
            //准备hash操作，绑定hash
            BoundHashOperations<String, Object, Object> operations = redisTemplate.boundHashOps(SECKILL_CHARE_PREFIX);
            session.getRelationSkus().forEach(seckillSkuVo -> {
                //生成随机码
                String token = UUID.randomUUID().toString().replace("-", "");
                String redisKey = seckillSkuVo.getPromotionSessionId().toString() + "-" + seckillSkuVo.getSkuId().toString();
                if (BooleanUtils.isFalse(operations.hasKey(redisKey))) {
                    //缓存我们商品信息
                    SeckillSkuRedisTo redisTo = new SeckillSkuRedisTo();
                    Long skuId = seckillSkuVo.getSkuId();
                    //1、先查询sku的基本信息，调用远程服务
                    R info = productFeignService.getSkuInfo(skuId);
                    if (info.getCode() == 0) {
                        SkuInfoVo skuInfo = (SkuInfoVo) info.getData(new TypeReference<SkuInfoVo>(){},"skuInfo");
                        redisTo.setSkuInfo(skuInfo);
                    }
                    //2、sku的秒杀信息
                    BeanUtils.copyProperties(seckillSkuVo,redisTo);
                    //3、设置当前商品的秒杀时间信息
                    redisTo.setStartTime(session.getStartTime().getTime());
                    redisTo.setEndTime(session.getEndTime().getTime());
                    //4、设置商品的随机码（防止恶意攻击）
                    redisTo.setRandomCode(token);
                    //序列化json格式存入Redis中
                    String seckillValue = JSON.toJSONString(redisTo);
                    operations.put(seckillSkuVo.getPromotionSessionId().toString() + "-" + seckillSkuVo.getSkuId().toString(),seckillValue);
                    //如果当前这个场次的商品库存信息已经上架就不需要上架
                    //5、使用库存作为分布式Redisson信号量（限流）
                    // 使用库存作为分布式信号量
                    RSemaphore semaphore = redissonClient.getSemaphore(SKU_STOCK_SEMAPHORE + token);
                    // 商品可以秒杀的数量作为信号量
                    semaphore.trySetPermits(seckillSkuVo.getSeckillCount());
                }
            });
        });
    }

    /**
     * 获取到当前可以参加秒杀商品的信息
     */
    //@SentinelResource(value = "getCurrentSeckillSkusResource",blockHandler = "blockHandler")
    @Override
    public List<SeckillSkuRedisTo> getCurrentSeckillSkus() {
    //    try (Entry entry = SphU.entry("seckillSkus")) {
    //        //1、确定当前属于哪个秒杀场次
    //        long currentTime = System.currentTimeMillis();
    //        //从Redis中查询到所有key以seckill:sessions开头的所有数据
    //        Set<String> keys = redisTemplate.keys(SESSION__CACHE_PREFIX + "*");
    //        for (String key : Objects.requireNonNull(keys)) {
    //            //seckill:sessions:1594396764000_1594453242000
    //            String replace = key.replace(SESSION__CACHE_PREFIX, "");
    //            String[] s = replace.split("_");
    //            //获取存入Redis商品的开始时间
    //            long startTime = Long.parseLong(s[0]);
    //            //获取存入Redis商品的结束时间
    //            long endTime = Long.parseLong(s[1]);
    //            //判断是否是当前秒杀场次
    //            if (currentTime >= startTime && currentTime <= endTime) {
    //                //2、获取这个秒杀场次需要的所有商品信息
    //                List<String> range = redisTemplate.opsForList().range(key, -100, 100);
    //                BoundHashOperations<String, String, String> hasOps = redisTemplate.boundHashOps(SECKILL_CHARE_PREFIX);
    //                assert range != null;
    //                List<String> listValue = hasOps.multiGet(range);
    //                if (listValue != null) {
    //                    return listValue.stream().map(item -> JSON.parseObject(item, SeckillSkuRedisTo.class)).collect(Collectors.toList());
    //                }
    //                break;
    //            }
    //        }
    //    } catch (BlockException e) {
    //        log.error("资源被限流{}",e.getMessage());
    //    }
    //    return null;
        return new ArrayList<>();
    }

    //public List<SeckillSkuRedisTo> blockHandler(BlockException e) {
    //    log.error("getCurrentSeckillSkusResource被限流了,{}",e.getMessage());
    //    return null;
    //}

    /**
     * 根据skuId查询商品是否参加秒杀活动
     */
    @Override
    public SeckillSkuRedisTo getSkuSeckilInfo(Long skuId) {
        //1、找到所有需要秒杀的商品的key信息---seckill:skus
        BoundHashOperations<String, String, String> hashOps = redisTemplate.boundHashOps(SECKILL_CHARE_PREFIX);
        //拿到所有的key
        Set<String> keys = hashOps.keys();
        if (keys != null && keys.size() > 0) {
            //4-45 正则表达式进行匹配
            String reg = "\\d+-" + skuId;
            for (String key : keys) {
                //如果匹配上了
                if (Pattern.matches(reg,key)) {
                    //从Redis中取出数据来
                    String redisValue = hashOps.get(key);
                    //进行序列化
                    SeckillSkuRedisTo redisTo = JSON.parseObject(redisValue, SeckillSkuRedisTo.class);
                    //随机码
                    long currentTime = System.currentTimeMillis();
                    assert redisTo != null;
                    Long startTime = redisTo.getStartTime();
                    Long endTime = redisTo.getEndTime();
                    //如果当前时间大于等于秒杀活动开始时间并且要小于活动结束时间
                    if (currentTime >= startTime && currentTime <= endTime) {
                        return redisTo;
                    }
                    redisTo.setRandomCode(null);
                    return redisTo;
                }
            }
        }
        return null;
    }


    /**
     * 当前商品进行秒杀（秒杀开始）
     */
    @Override
    public String kill(String killId, String key, Integer num) throws InterruptedException {
        //获取当前用户的信息
        MemberRespVo user = LoginUserInterceptor.loginUser.get();
        //1、获取当前秒杀商品的详细信息从Redis中获取
        BoundHashOperations<String, String, String> hashOps = redisTemplate.boundHashOps(SECKILL_CHARE_PREFIX);
        String skuInfoValue = hashOps.get(killId);
        if (StringUtils.isEmpty(skuInfoValue)) {
            return null;
        }
        //(合法性效验)
        SeckillSkuRedisTo redisTo = JSON.parseObject(skuInfoValue, SeckillSkuRedisTo.class);
        Long startTime = redisTo.getStartTime();
        Long endTime = redisTo.getEndTime();
        long currentTime = System.currentTimeMillis();
        //判断当前这个秒杀请求是否在活动时间区间内(效验时间的合法性)
        if (currentTime >= startTime && currentTime <= endTime) {
            //2、效验随机码和商品id
            String randomCode = redisTo.getRandomCode();
            String skuId = redisTo.getPromotionSessionId() + "-" +redisTo.getSkuId();
            if (randomCode.equals(key) && killId.equals(skuId)) {
                //3、验证购物数量是否合理和库存量是否充足
                Integer seckillLimit = redisTo.getSeckillLimit();
                //获取信号量
                String seckillCount = redisTemplate.opsForValue().get(SKU_STOCK_SEMAPHORE + randomCode);
                int count = Integer.parseInt(Objects.requireNonNull(seckillCount));
                //判断信号量是否大于0,并且买的数量不能超过库存
                if (count > 0 && num <= seckillLimit && count > num ) {
                    //4、验证这个人是否已经买过了（幂等性处理）,如果秒杀成功，就去占位。userId-sessionId-skuId
                    //SETNX 原子性处理
                    String redisKey = user.getId() + "-" + skuId;
                    //设置自动过期(活动结束时间-当前时间)
                    long ttl = endTime - currentTime;
                    Boolean flag = redisTemplate.opsForValue().setIfAbsent(redisKey, num.toString(), ttl, TimeUnit.MILLISECONDS);
                    if (BooleanUtils.isTrue(flag)) {
                        //占位成功说明从来没有买过,分布式锁(获取信号量-1)
                        RSemaphore semaphore = redissonClient.getSemaphore(SKU_STOCK_SEMAPHORE + randomCode);
                        //TODO 秒杀成功，快速下单
                        boolean semaphoreCount = semaphore.tryAcquire(num, 100, TimeUnit.MILLISECONDS);
                        //保证Redis中还有商品库存
                        if (semaphoreCount) {
                            //创建订单号和订单信息发送给MQ
                            // 秒杀成功 快速下单 发送消息到 MQ 整个操作时间在 10ms 左右
                            String orderSn = IdWorker.getTimeId();
                            SeckillOrderTo orderTo = new SeckillOrderTo();
                            orderTo.setOrderSn(orderSn);
                            orderTo.setMemberId(user.getId());
                            orderTo.setNum(num);
                            orderTo.setPromotionSessionId(redisTo.getPromotionSessionId());
                            orderTo.setSkuId(redisTo.getSkuId());
                            orderTo.setSeckillPrice(redisTo.getSeckillPrice());
                            rabbitTemplate.convertAndSend("order-event-exchange", "order.seckill.order", orderTo);
                            return orderSn;
                        }
                    }
                }
            }
        }
        return null;
    }

}
